Plant Based Diets & Optimal Health: Going All The Way Greetings Everyone!

This week, I will be addressing questions that were posed to me over the past week and that I am often asked.

QUESTION: ”I am trying to adopt a healthy diet to improve my health and reduce the risk of disease and/or to control it. Is it necessary to be 100% vegetarian to accomplish this? Could similar or the same results be achieved with limited amounts of animal protein (i.e., organic meat form wild salmon, and/or range free chicken breast, and/or egg whites)?”

You ask a great question and if I understand it correctly, you are asking, "Is there any benefit to a 100% plant diet vs. a (let's say) 95-99% plant-based diet, assuming both are equally planned to be as healthy as possible?"Unfortunately, no one knows for sure. There is an abundance of evidence showing that reducing the amount of animal food and increasing the amount of plant food in one's diet brings tremendous health benefits. This is especially true if the plant food is based on unrefined/unprocessed plant foods that are in their more natural state without all the added sodium, refined sugars, saturated fat, hydrogenated fat and/or or trans fat often found in processed plant foods. However, I do not know of any evidence supporting the assertion that making it a 100% plant-based (or vegan) diet is required in order to achieve optimal health benefits. In addition, there are other non-dietary issues to consider, such as activity/exercise levels and nicotine and alcohol use.

There are some studies, like The China Study, by Dr. T. Colin Campbell, which supports the concept that the less animal food and the more plant foods in one’s diet the better. But interestingly, while some of these studies are often used to defend a vegan diet, none of the studies show that complete abstinence from animal food is best. Why? This is because in many of these studies, there were no groups in the studies that completely abstained from animal foods. Proving less is better doesn't automatically mean that none is optimal, unless, of course, there are studies to prove this assertion, also. QUESTION: “Have there been any studies done on the long-term health and mortality of vegans?”

Yes, there are studies done on vegans on this issue, and the best data comes out of the work done in The Seventh-Day Adventist Church Health Study. Seventh-Day Adventists are a unique population to study in this regard, because they are less likely to smoke and may exercise more than the typical person in the US and many follow a vegetarian diet. The Seventh-Day Adventist Church Health Study (1), which was funded by the U.S. National Institutes of Health and was featured on the cover story of the November 2005 issue of National Geographic magazine, is the only major ongoing study in the U.S. on the general health and mortality of vegetarians that I know of. An overview of all the research on the Seventh-day Adventists can be seen at the website of Loma Linda University here.

For the study, data was collected from 1976-1988. Of the 34,192 participants, of which all were members of the Seventh-Day Adventist Church: 29 % were vegetarian, and another 20% described themselves as semi-vegetarian (ate meat fewer than one time per week but more than once per month), while 7-10 % of the vegetarians were vegan. This equates to about 2.5% of the study population being vegans. But remember, the results cited are for the entire study population, which included many vegetarian and non-vegetarian members, not just the vegans.

This study has shown that the average Adventist in California lives four to ten years longer than the average Californian as a result of their different lifestyle choices. Among the lifestyle choices investigated, a vegetarian diet was estimated to confer an extra 1.5 to 2 years of life. What this means is that at birth, an infant who would grow up to be a California Adventist male would be expected to live 78.5 years, a female California Adventist, 82.3 years. If the California Adventist was also vegetarian, life expectancy at birth increased to 80.2 years for men and 84.8 years for women. Compare this to a US male whose life expectancy at birth is 73 years and a US female who can expect to live 79.7 years (NOTE: These numbers are based on life expectancy at the time the study was done).

The research found that in addition to their healthy, low-fat vegetarian diet rich in nuts and beans, Adventists live longer because they do not smoke or drink. Their cohesive social networks is considered another contributor to their extended lifespan.

In July 2002 at the World Vegetarian Congress in Edinburgh Scottland, Paul Appleby presented data on “The Long Term Health of Western Vegetarians.” Paul is a founding member of the International Vegetarian Union Science group and Secretary of the Oxford Vegetarians. Professionally, he is the senior statistician at the Cancer Epidemiology Unit of the University of Oxford and has co-authored several of the studies on vegetarians.

The data from five large population studies were grouped together in 1996 to give results for 76,000 persons of whom nearly 28,000 were vegetarians (2). In the analysis, there were 8,330 deaths between the ages of 16 to 89 after an average of 10.6 years follow-up. The results of the pooled analysis suggested that vegetarians may have a slightly lower overall mortality than comparable non-vegetarians (by about 5%), although this result was not statistically significant. Vegetarians were also found to have a significantly lower mortality for ischemic heart disease (by about 25%), but not for other common causes of death. In addition, there were no significant differences between vegetarians and nonvegetarians in mortality from stroke, stomach cancer, colorectal cancer, lung cancer, breast cancer, prostate cancer, or all other causes combined.

In reviewing the data on British vegetarians, Paul reported..

“A recent re-analysis of data from the two British studies found no differences in overall death rates between vegetarians and non-vegetarians. The researchers concluded that the low mortality of British vegetarians compared with the general population “may be attributed to non-dietary lifestyle factors such as a low prevalence of smoking and a generally high socio-economic status, or to aspects of the diet other than the avoidance of meat and fish”. (3)

His conclusions:-much of the benefit is attributable to non-dietary lifestyle factors such as the avoidance of smoking and a high socio-economic status;- vegetarians have similar mortality to comparable non-vegetarians for all causes of death combined, stroke and the most common cancers;- a vegetarian diet is not a panacea

A 21 years study of German vegetarians which included 1,225 vegetarians and 679 health-conscious non-vegetarians, found that both groups (vegetarians and health-conscious non-vegetarians) had a lower mortality compared with the general population. However, the low incidence of smoking and the moderate to high level of physical activity among the vegetarians, not their strictly vegetarian diet, were the key factors associated with their reduced overall mortality. Only the nonsignificant reduction in mortality from ischemic heart diseases in the vegetarians could be explained partly by their avoidance of meat. (4)Question: What about the vegans? In the Seventh Day Adventist Health Study (mentioned above), in comparison with regular meat-eaters, mortality from ischemic heart disease was 26% lower in the vegans. However, mortality from ischemic heart disease among the vegans was slightly higher than among the fish-eaters and vegetarians, and only slightly less than the occasional meat-eaters. But remember, we have to be careful about the findings, as the total number of vegans in the study was small.

The following summary on the health of the vegans in the Seventh Day Adventist study is from Diet, Life Expectancy and Chronic Disease. Studies of Seventh-Day Adventists and Other Vegetarians. Gary E Fraser. Oxford: Oxford University Press, 2003.

From the chapter, Risk Factors and Diseases among Vegans, page 239:

1. Vegans are thinner than other vegetarians.

2. Levels of blood cholesterol and of blood LDL cholesterol are lower in vegans than in other vegetarians. HDL levels may also be lower, but the evidence is not consistent.

3. Blood pressure levels in vegans appear to be modestly, but significantly lower than those in other vegetarians. This statement is based mainly on a large British data set.

4. Data on other risk factors are too sparse to allow meaningful comparisons between vegans and others.

5. Conclusions about disease events among vegans are also hampered by the low numbers of subjects in studies, but it seems unlikely that there are large differences in disease experiences between vegans and other vegetarians. Studies that include more vegans would be necessary to detect any small or moderate differences.

The California Adventist results did raise the possibility of higher cancer mortality in vegans (with a borderline statistical significance), but this needs confirmation from other studies to carry much conviction.

(NOTE: I do not know of any other evidence supporting the cancer issue and a healthy vegan diet is in line with most all dietary recommendations to reduce cancer risk.)

A 2006 review, Health effects of vegetarian and vegan diets (5) coauthored by Paul Appleby, found that while vegans generally weight less and have lower cholesterol levels, they also have higher homocysteine levels and low intakes of vitamin B12, calcium and omega 3 fatty acids. In addition, while the vegetarians had a slight reduction in mortality from heart disease, there was no clear difference in cancer rates and little difference in other major causes of death or all-cause mortality.

The latest, a 2007 review of 7,947 men and 26,749 women aged 20-89 years, including 19,249 meat-eaters, 4901 fish-eaters, 9,420 vegetarians and 1,126 vegans in the Oxford cohort of the European Prospective Investigation into Cancer and Nutrition (6) found a higher fracture risk in the vegans which appeared to be a consequence of their considerably lower calcium intake. The authors concluded, “An adequate calcium intake is essential for bone health, irrespective of dietary preferences".

Now, I am not arguing against veganism or vegetarianism, I am only trying to help answer a valid question. In addition, it is a key point to remember that veganism is not a “diet” per see, it is simply a philosophy that includes dietary restrictions. Veganism is clear on exactly what not to eat (animal products), but not so clear on exactly what to eat! A vegan diet and its restrictions per se may not always be healthy. For example, one can live on potato chips, French fries and ketchup and still be a “vegan,” but is that healthy?

What is clear is that a vegan and/or vegetarian diet in and of itself, does not automatically equate to a healthy diet. Regardless of dietary preference, the principles of a healthy lifestyle and diet must be followed. Eliminating animal products in not a clear cut assurance of dietary excellence or optimal health. There are other lifestyle-related factors that must also be followed in relation to activity/exercise, nicotine and alcohol that may be as important, if not more important, than the changes in diet.

These health issues may have nothing to do with the moral, ethical, religious and/or philosophical reasons on why some people choose to become a vegan but must be considered if someone wants to optimize their health and longevity. If you become a vegan or vegetarian for health reasons, it is important to realize that doing so is not the final step in the journey to health, but only what could be a step in the journey to following a healthy diet and lifestyle and reducing your risk for disease.

With regard to your original question, my recommendation is:

For reducing your risk for disease and optimal health, focus your attention and efforts on the 95-99% (that is plant-based) and getting THAT right, and not the 1-5% (that may be animal-based). And please, do not lose focus and forget about the other non-dietary lifestyle related issues (i.e, smoking, drinking, exercise, etc) that are as important, if not more important, than diet.